Update get_bucket to take a Bucket object or string (#7856)

* Updated class method get_bucket to take Bucket object as part of Storage Client redesign.

storage/google/cloud/storage/client.py

@@ -202,28 +202,53 @@ def batch(self):
         """
         return Batch(client=self)
 
-    def get_bucket(self, bucket_name):
-        """Get a bucket by name.
+    def get_bucket(self, bucket_or_name):
+        """API call: retrieve a bucket via a GET request.
 
-        If the bucket isn't found, this will raise a
-        :class:`google.cloud.exceptions.NotFound`.
+        See
+        https://cloud.google.com/storage/docs/json_api/v1/buckets/get
 
-        For example:
+        Args:
+            bucket_or_name (Union[ \
+                :class:`~google.cloud.storage.bucket.Bucket`, \
+                 str, \
+            ]):
+                The bucket resource to pass or name to create.
 
-        .. literalinclude:: snippets.py
-            :start-after: [START get_bucket]
-            :end-before: [END get_bucket]
+        Returns:
+            google.cloud.storage.bucket.Bucket
+                The bucket matching the name provided.
 
-        This implements "storage.buckets.get".
+        Raises:
+            google.cloud.exceptions.NotFound
+                If the bucket is not found.
 
-        :type bucket_name: str
-        :param bucket_name: The name of the bucket to get.
+        Examples:
+            Retrieve a bucket using a string.
+
+            .. literalinclude:: snippets.py
+                :start-after: [START get_bucket]
+                :end-before: [END get_bucket]
+
+            Get a bucket using a resource.
+
+            >>> from google.cloud import storage
+            >>> client = storage.Client()
+
+            >>> # Set properties on a plain resource object.
+            >>> bucket = client.get_bucket("my-bucket-name")
+
+            >>> # Time passes. Another program may have modified the bucket
+            ... # in the meantime, so you want to get the latest state.
+            >>> bucket = client.get_bucket(bucket)  # API request.
 
-        :rtype: :class:`google.cloud.storage.bucket.Bucket`
-        :returns: The bucket matching the name provided.
-        :raises: :class:`google.cloud.exceptions.NotFound`
         """
-        bucket = Bucket(self, name=bucket_name)
+
+        bucket = None
+        if isinstance(bucket_or_name, Bucket):
+            bucket = bucket_or_name
+        else:
+            bucket = Bucket(self, name=bucket_or_name)
 
         bucket.reload(client=self)
         return bucket

storage/tests/unit/test_client.py

@@ -261,7 +261,7 @@ def test_batch(self):
         self.assertIsInstance(batch, Batch)
         self.assertIs(batch._client, client)
 
-    def test_get_bucket_miss(self):
+    def test_get_bucket_with_string_miss(self):
         from google.cloud.exceptions import NotFound
 
         PROJECT = "PROJECT"
@@ -290,7 +290,7 @@ def test_get_bucket_miss(self):
             method="GET", url=URI, data=mock.ANY, headers=mock.ANY
         )
 
-    def test_get_bucket_hit(self):
+    def test_get_bucket_with_string_hit(self):
         from google.cloud.storage.bucket import Bucket
 
         PROJECT = "PROJECT"
@@ -320,6 +320,68 @@ def test_get_bucket_hit(self):
             method="GET", url=URI, data=mock.ANY, headers=mock.ANY
         )
 
+    def test_get_bucket_with_object_miss(self):
+        from google.cloud.exceptions import NotFound
+        from google.cloud.storage.bucket import Bucket
+
+        project = "PROJECT"
+        credentials = _make_credentials()
+        client = self._make_one(project=project, credentials=credentials)
+
+        nonesuch = "nonesuch"
+        bucket_obj = Bucket(client, nonesuch)
+        URI = "/".join(
+            [
+                client._connection.API_BASE_URL,
+                "storage",
+                client._connection.API_VERSION,
+                "b",
+                "nonesuch?projection=noAcl",
+            ]
+        )
+        http = _make_requests_session(
+            [_make_json_response({}, status=http_client.NOT_FOUND)]
+        )
+        client._http_internal = http
+
+        with self.assertRaises(NotFound):
+            client.get_bucket(bucket_obj)
+
+        http.request.assert_called_once_with(
+            method="GET", url=URI, data=mock.ANY, headers=mock.ANY
+        )
+
+    def test_get_bucket_with_object_hit(self):
+        from google.cloud.storage.bucket import Bucket
+
+        project = "PROJECT"
+        credentials = _make_credentials()
+        client = self._make_one(project=project, credentials=credentials)
+
+        bucket_name = "bucket-name"
+        bucket_obj = Bucket(client, bucket_name)
+        URI = "/".join(
+            [
+                client._connection.API_BASE_URL,
+                "storage",
+                client._connection.API_VERSION,
+                "b",
+                "%s?projection=noAcl" % (bucket_name,),
+            ]
+        )
+
+        data = {"name": bucket_name}
+        http = _make_requests_session([_make_json_response(data)])
+        client._http_internal = http
+
+        bucket = client.get_bucket(bucket_obj)
+
+        self.assertIsInstance(bucket, Bucket)
+        self.assertEqual(bucket.name, bucket_name)
+        http.request.assert_called_once_with(
+            method="GET", url=URI, data=mock.ANY, headers=mock.ANY
+        )
+
     def test_lookup_bucket_miss(self):
         PROJECT = "PROJECT"
         CREDENTIALS = _make_credentials()